Rotating filter

ABSTRACT

The invention relates to a device for filtering liquids, comprising two shafts ( 11 ) which are parallel to each other or at an acute angle to each other. Each shaft ( 1 ) carries a stack of discs ( 2 ) which extend perpendicularly to the shaft axis and which are connected to the shaft ( 2 ) in a rotationally fixed manner. The discs ( 2 ) of one disc stack are engaged in the intermediate spaces between the discs of an adjacent discs stack. At least one of the shafts ( 1 ) is drivable and at least one of the shafts is hollow and is provided with bores ( 1 - 2 ). Some of the discs have channels ( 2 - 4 ) inside them which are conductively connected to the inside of their hollow shaft ( 1 ). A ring-shaped distancing element ( 3 ) is located between each pair of adjacent discs ( 2 ) of a shaft. According to the invention, a device of this type is characterized as follows: the distancing element ( 3 ) is sealed in relation to the adjacent discs ( 2 ); said distancing element ( 3 ) is connected to the shaft ( 1 ) in a rotationally fixed manner; and the support ring ( 3 - 1 ) is oversized in relation to the shaft ( 1 ) so that a channel ( 4 ) is formed between the inner surface of the support ring ( 3 - 1 )and the outer surface of the shaft ( 1 ), this channel extending at least over part of the length of the shaft ( 1 ).

[0001] The invention relates to a device for filtering liquids. Such a device is described for example in DE 100 19 672 A1.

[0002] Devices of this kind serve the cross-flow permeation of free-flowing media. They contain at least two shafts, onto which in each case many disk-shaped diaphragm bodies are arranged parallel to each other and in mutual distance. The shafts are hollow, and the diaphragm disks are made of ceramic material and are burred with radial channels. Between the radial channels and the inside of the hollow shaft consists a conducting connection. The liquid to be filtered arrives from the outside through the porous material of the diaphragm body into the channels, and from there into the hollow shaft.

[0003] The shafts mentioned run parallel to each other, so that also the diaphragm disks of two each other adjacent disk stacks are arranged parallel to each other. The shafts are arranged so close next to each other in such a manner that the disks of two disk stacks engage interlocking.

[0004] The disks do not have to have the design mentioned from porous ceramic material. There are also applications, in which some disks are built up as so-called dummy disks. It is also possible to make the disks from strainer bodies. Also combinations of the designs mentioned are conceivable, for example the combination strainer body-diaphragm body. Following only the term “disks” is used.

[0005] In order to achieve a large productivity as possible, as many disks as possible are to sit on a shaft. The disks therefore must be arranged as close as possible. On the other hand however it is to be made certain that the disks of one stack do not touch the disks of the other stack. Therefore an accurate axial positioning of the disks on their shafts is required.

[0006] For the purpose of positioning distancing elements are arranged between two each other adjacent disks. Also for the purpose of an accurate axial positioning the total disk stack is compressed, for example by a nut, which is screwed onto the hollow shaft concerned on one of its ends, and which exerts a suitable pressure on the multiplicity of disks with the distancing elements present between them. A spring assembly can be mounted between nut and hollow shaft.

[0007] Furthermore it must be ensured that the disks are positioned perfectly also in the radial direction, and that with the rotation of the shaft with the disks present on it concentricity is ensured and radial deflecting is avoided. Furthermore it must be ensured that the torque is transferred from the rotating hollow shaft equally onto all disks of the hollow shaft.

[0008] Finally a perfect seal between the disks and the distancing elements must be provided, so that no liquid passes through between the disks and the distancing elements to the hollow shaft.

[0009] All these requirements could not be fulfilled to the desired extent with the well-known devices.

[0010] It is the task of the invention to develop a device of the initially described kind in such a manner that a perfect axial and radial positioning of the disks results, that the impermeability against passing of liquid between the disks and the distancing elements is ensured, that the torque is transferred equally to all disks, and that the whole device with all its many component parts can be easily and reliably assembled.

[0011] The features of patent claim 1 solve this task.

[0012] The central idea of the invention consists in the design of the distancing element. Said distancing element contains one support ring as well as two sealing rings.

[0013] The support ring is dimensioned in such a manner that it is oversized in relation to the hollow shaft. Between the lateral surface of the hollow shaft and the inner surface of the support ring thus a ring-shaped gap area consists. This gap area extends over the total length of the hollow shaft. It can be dimensioned amply, so that a free current is possible and deposits are avoided. This is for example of great importance for applications in the pharmaceutical industry.

[0014] For the purpose of positioning the support ring exhibits projecting parts, which are supported by the lateral surface of the hollow shaft. The projecting parts can taper—when viewed in a cross-section perpendicular to the axis—towards the lateral surface, so that between projecting part and lateral surface of the hollow shaft only line contact prevails.

[0015] In addition a device is planned to create a rotationally fixed connection between hollow shaft and support ring. Due to the tight restraint between the support rings, the sealing components and the disks, the disks are carried forward by the distancing elements through friction.

[0016] One of the projecting parts mentioned can engage in a suitable recess of the hollow shaft parallel to the axis, creating a rotationally fixed connection.

[0017] The sealing rings mentioned are located on the two faces of each support ring. They create the desired sealing connection as well as the necessary torque transmission between support ring and disk.

[0018] The invention is described in more detail with the drawing. The following is detailed represented:

[0019]FIG. 1 shows a device with filter plates according to the invention in a diagrammatic front view.

[0020]FIG. 2 shows the subject of FIG. 1 in a top view.

[0021]FIG. 3 shows a modified design example of the subject of FIG. 1, again in a top view.

[0022]FIG. 4 shows a section of the subject of FIG. 1.

[0023]FIG. 5 shows an enlarged view of a ring half of the distancing element shown in FIG. 4.

[0024]FIG. 6 shows a cut through the subject of FIG. 4, said cut made in the area of the distancing element, diagrammatic in an enlarged view.

[0025]FIG. 7 pictorializes parallel next to each other on the one hand the length of the hollow shaft, on the other hand the added lengths of the disks, the support rings as well as the sealing rings.

[0026]FIG. 8 shows in a diagrammatic view a device according to the invention; from this the details of the over-mounting are recognizable.

[0027]FIG. 9 shows a section of the subject of FIG. 8 in the area of the free end of a shaft.

[0028]FIG. 10 shows a design example of the invention with a twin arrangement of two devices according to the invention.

[0029]FIG. 11 shows a design example of the invention, again with a twin arrangement of two devices, however with a partition wall present between them.

[0030]FIG. 12 shows the subject of FIG. 11 in a vertical position.

[0031]FIG. 13 shows in diagrammatic view a design example of a reservoir with conical casing.

[0032]FIG. 14 shows a design example of a twin arrangement of two devices with shafts, which are mounted in each case in the center area of their length.

[0033]FIG. 15 shows in diagrammatic view a number of disk stacks with shafts inclined towards each other.

[0034]FIG. 16 shows in a cross-section perpendicular to the axis a device according to the invention in a special arrangement.

[0035] As can be seen in FIGS. 1 and 2, the device exhibits two hollow shafts 1, 1′. Each hollow shaft carries a stack of disks 2, 2′. The two shafts 1, 1′ and the disk stacks are in a reservoir 10. The reservoir exhibits an inlet 10.1 and an outlet 10.2.

[0036] The two hollow shafts 1, 1′ are driven—see FIG. 2, seen in top view on the ends of the shafts in the clockwise direction. They both can run also against the clockwise direction. Anyhow the rotation in the same direction of rotation is favorable.

[0037] In the present case the disks serve the purpose of filtration. They are composed of a porous ceramic material and exhibit internal channels. The channels are in conducting connection with the insides of the hollow shafts 1, 1′.

[0038] The medium to be treated arrives in the inside of the reservoir 10 through the inlet 10.1. The filtrate/permeate enters then through the pores of the ceramic material the channels mentioned and arrives from there in the inside of the two hollow shafts 1, 1′. It emerges then at the upper ends of the hollow shafts—see the two arrows pointing upward.

[0039] Whatever amount is not able to penetrate through the pores of the ceramic material, arrives as residue at the outlet 10.2 of the reservoir 10.

[0040] In the design example shown in FIG. 3 three shafts with three disk stacks are represented. The disks run here in the same direction of rotation as well. In addition, a direction of rotation moving in opposite directions could be selected.

[0041]FIG. 4 shows substantial details of the invention. One recognizes again a hollow shaft 1, furthermore in cross section two diaphragm disks 2, which are designed identically. The diaphragm disks contain in each case a supporting body 2.1 made from porous, ceramic material. Furthermore they contain a diaphragm coating 2.3, which is carried by the supporting body and is located at its external surface.

[0042] The distancing element 3 is crucial. It is ring-shaped. It encloses the hollow shaft 1.

[0043] The distancing element 3 is put together from a support ring 3.1 as well as of two sealing rings 3.2, 3.2.

[0044] The shape of the distancing element 3 can be seen more accurately in FIGS. 5 and 6.

[0045] The support ring 3.1 is oversized in relation to the hollow shaft 1. Its internal circumferential area has a larger radius than the lateral surface of the hollow shaft 1. For this reason a ring-shaped gap 4 is formed between these two areas—see FIG. 4.

[0046] Support ring 3.1 exhibits a peculiarity. As can be seen in FIGS. 4, 5 and 6, it is provided with projecting parts. The projecting parts 3.1.1 and 3.1.2 are of identical design, while projecting part 3.1.3 is different. All three projecting parts are wedge-shaped or triangular in the sectional view according to FIG. 6. They exhibit a point, which is directed towards the hollow shaft 1. But the points of the projecting parts 3.1.1 and 3.1.2 support themselves on the lateral surface of the hollow shaft 1, while the projecting part 3.1.3 engages in a groove 1.1 of the hollow shaft 1. Projecting part 3.1.3 and groove 1.1 create together a device for building a rotationally fixed connection between hollow shaft 1 on the one hand and support ring 3.1 on the other hand, therefore at the same time between hollow shaft 1 and the stack of the disks 2.

[0047] The ring-shaped gap 4 between the support ring 3.1 and the hollow shaft 1 can again be seen in FIG. 6. This ring area 4 is interrupted in circumferential direction only by the projecting parts 3.1.1, 3.1.2 and 3.1.3, extends however over the total length of the hollow shaft 1.

[0048] As can be seen in FIG. 4, each disk 2 exhibits in its inside a channel 2.4-here shown largely exaggerated. Channel 2.4 of each disk 2 is with the ring-shaped gap 4 and the inside of the hollow shaft 1 in conducting connection, by means of bores 1.2, which extend over the total length of the hollow shaft 1. The gap 4 can be dimensioned amply, so that a free current of the medium and thus a good rinsing are possible, without the danger of deposits caused by dead corners.

[0049] The dimensioning of projecting part 3.1.3 and groove 1.1, represented in FIG. 6, can also be helpful. The groove 1.1 has a larger opening angle than the angle of the projection part 3.1.3 at its point. Thus a certain flow takes place also within the area of the point of the projecting part 3.1.3.

[0050] The projecting parts 3.1.1, 3.1.2 and 3.1.3 represent a centering of the support ring 3.1 on the hollow shaft 1 and position thereby at the same time the disks 2 of the total disk stack, which results from the following.

[0051] The distancing element carries the two mentioned sealing rings 3.2 on its two faces. In the present case these two sealing rings are connected by a bar 3.3. The sealing rings 3.2 and the bar 3.3 are one-piece. The bar has thereby no functional meaning, but is suitable for production reasons. It could also be positioned radially further outside, in such a manner that the two sealing rings 3.2, 3.2 exhibit together with the bar 3.3 in the representation according to FIG. 4 a U-shaped profile.

[0052] The perspective representation of the distancing element 3 according to FIG. 5 shows the following: In the left-hand figure the sealing ring 3.2 can be seen in a condition, in which it is fastened to the support ring 3.1 by vulcanizing, however without being machined. In the right-hand representation the two sealing rings 3.2, 3.2 are machined, here a seat is worked out, which is rectangular in this representation. The purpose of this seat is to receive the concerning disk 2. The accurate seat can be also realized directly during the vulcanization. The seat face can be profiled, for example in a wave shape or saw tooth shape.

[0053] The total disk stack including the multiplicity of distancing elements 3 present between them is restrained evenly in axial direction during assembly. An axial pressure is exerted, so that the components mentioned are pressed together. This can be achieved for example by screwing a nut onto one end of the hollow shaft 1; here the nut exercises an axial load on the there present distancing element 3 when it is tightened. The contact pressure is passed symmetrical and without friction losses to all other disks 2 and distancing elements 3.

[0054] The special design according to the invention of the carrying component 3 leads to the fact that the distancing elements 3 can slide in axial direction basically frictionless on the lateral surface of the hollow shaft 1 when restrained as mentioned. Thereby a pressure drop of the clamping force over the length of the hollow shaft 1 is avoided.

[0055] The clamping force is necessary, in order to transfer the torque that is transferred by the shaft 1 to the support ring 3.1 also to the disks 2. A frictional connection between the disks 2 and the sealing rings 3.2 is created by the restraint mentioned, so that when the hollow shaft 1 is turned all disks are taken along.

[0056] The following benefit, which results from the invention, is especially important: The axial clamping of the disks 2 and the distancing elements 3 leads to an accurate positioning of the disks 2 in axial direction. It is important that in an arrangement according to the FIGS. 1 to 3 mutual starting (touching) of the disks of one stack with the disks of an adjacent stack is avoided. If a pressure drop over the length of the hollow shaft 1 would occur, caused by friction between gasket and hollow shaft, then disks and distancing elements would be in the upper area impinged with pressure to a higher extent, i.e., where the axial clamping force is initiated, than disks and distancing elements in a more distant area. Thereby axial deviations in the dimension would occur, which add on to themselves.

[0057] The material of the support rings 3.1 should be a relatively hard, to a large extent incompressible material, for example high-grade steel, in special cases titanium, ceramic(s), carbon, synthetic, e.g. enforced.

[0058] As materials for the sealing rings ductile and/or elastic ductile materials come into consideration, e.g. elastomers, easily ductile metals and/or their alloys as well as graphite.

[0059] An important point is the problem of the expansion of the whole unit during a temperature rise. The hollow shaft 1 will generally be made of high-grade steel. Its thermal expansion can be easily determined.

[0060] The thermal expansion of the hollow shaft is to be compared to the thermal expansion of its surrounding components, i.e. the disks 2 consisting of ceramic(s) or the like, the carrying components 3.1 and the sealing rings 3.2. Hereby it is desirable or necessary that these two components—hollow shaft on the one hand and disks, carrying components, sealing rings on the other hand—show the same thermal expansion behavior. This is usually not the case. Therefore according to a further thought of the invention it is recommended to select concerning the materials of the three components last mentioned—disks, support rings, sealing rings—materials that lead to the desired result when interconnected. See for this FIG. 7.

[0061]FIG. 8 shows the nature of the invention well. A first stack of disk-shaped bodies 2, which sit on a shaft 1, can be seen, furthermore a second stack of disk-shaped bodies 2′, which sit on a shaft 1′. The disks 2, 2′ are in the present case ring-shaped disks. They could also have a different shape.

[0062] These two structural components, in each case containing shaft and disks, are located in a reservoir 10. Said reservoir exhibits a tubular, cylindrical casing 10.3, a base 10.4 as well as a lid 10.5. The reservoir does not have to be a regular cylinder. It can for example have the cross-section of a polygon. The reservoir does not even have to be cylindrical. It can be for example in the shape of a truncated cone.

[0063] The shafts 1, 1′ are passed through the lid 10.5. They are mounted in the lid and sealed. The bearing and the seal are not represented here in detail.

[0064] On the exterior of the lid 10.5 are, likewise not represented, drive units for the two shafts 1, 1′.

[0065] It is important that the two shafts 1, 1′ are over-mounted. They thus project freely out of the lid 10.5, without the need for a support of the two shafts 1, 1′ at their other ends In the present case thus a distance between the free ends of the shafts 1, 1′ and the base 10.4 prevails.

[0066]FIG. 9 shows a modification of the subject of FIG. 8. The right end of the shaft 1 can be seen. A recess 5.4.1 is intended in the base 5.4. Said recess centers the free end of the shaft 1 and receives it.

[0067] Such a receiver 10.4.1 can be suitable. However, it is not absolutely necessary. In each case no seal is required at the free end of the two shafts 1, 1′. Anyhow medium flows around the free shaft end during the operation.

[0068] Particularly interesting design examples are represented in the FIGS. 10 and 11. Two devices according to the invention are united with one another. All shafts run parallel to each other. The two reservoirs 10, 10′ are joined. They exhibit in each case a lid 10.5, 10.5′ as well as a cylindrical, tubular casing 10.3, 10.3′. The casings 10.3, 10.3′ carry in each case a ring flange 10.7, 10.7′. The two reservoirs are united with one another at this ring flange, for example by a mutual screw connection. This way the two reservoirs 10, 10′ enclose only one area without partitioning. The casings 10.3, 10.3′ can be also only one component, consist thus for example of a continuous reservoir casing.

[0069] The design example according to FIG. 11 concerns again a twin version, which contains two reservoirs. The design is basically the same as in the design example according to FIG. 10. One difference consists however in the fact that instead of the two flanges 10.7, 10.7′ a partition 10.8 is intended here. This way two separate non-filtrate areas are created.

[0070] The whole device according to FIG. 11 is mounted on a rolling surface or a guide way 6. The two lids 10.5, 10.5′ leave can be moved in axial direction for disassembly, together with the shafts and the disks located on the shafts, either with or without the reservoir casing. This way easy assembly and disassembly are possible.

[0071] The twin design according to FIGS. 10 and 11 has numerous benefits. First it is simpler in its design than two single devices. It contains in both cases the base, which in the design example according to FIG. 8 has to be present—see there base 10.4. In the case of the design example according to FIG. 10 the base is eliminated basically without a substitute—apart from the ring flanges 10.7, 10.7′. But also the ring flanges 10.7, 10.7′ can be eliminated, for example if a only one continuous reservoir casing is intended. In the case of the design example according to FIG. 11 the two otherwise necessary bases are replaced by the here present partition 10.8.

[0072] In the design example according to FIG. 11 the partition 10.8 can exhibit passages. These passages are not represented here. Such passages can be standard bores. In addition, the openings can have an adjustable or regulated cross-section of the opening. From this result interesting possibilities for operating the whole device.

[0073]FIG. 12 shows again a whole device similar to the one according to FIG. 11, united from two single devices. The whole device can be swiveled around a horizontal swiveling axis 10.9, so that the whole device can be swiveled from the vertical position represented here into a horizontal position. This can be very practical for the purpose of assembly and disassembly, for example during maintenance work.

[0074]FIG. 14 shows again design example of the device in twin arrangement with two single devices similar to the design examples according to the FIGS. 10 and 11. Here are also two reservoirs intended. Said reservoirs exhibit lids 5.5, 5.5′ as well as casings 5.3, 5.3′.

[0075] Contrary to the design examples according to the FIGS. 10 and 11 however the lids 5.5, 5.5′ are turned towards each other. Furthermore the shafts 1, 1′, 2, 2′ are mounted in the lids and face with their free ends outward, contrary to the design examples according to the FIGS. 10 and 11, in which the free ends of the shafts are facing against each other.

[0076] The drive unit of the shafts is located between the two single devices. FIG. 15 shows a configuration of disk stacks in diagrammatic view, in which the three shafts 1, 2, 1′ are inclined towards each other and the disks are plate-like shaped.

[0077] All devices according to the invention, shown here, can exhibit the following features:

[0078] The speeds of the stacks consisting of shafts and disks can be variable, adapted to the needs of the product. They range preferably in the speed range between 10 and 1000 rpm.

[0079] All stacks rotate in the same direction of rotation. The difference speed which two plane elemets opposite each other of two adjacent disks exhibit within the overlap area, is relevant. This difference speed can range between 1 and 20 m/s. The best range is between 2.5 and 7 m/s.

[0080] The disks can be classical filter disks, made from a porous ceramic material. But they can also be hollow strainer bodies. Finally at least some of the disks can be designed as so-called dummy disks. Likewise a composite-design is possible, for example unlimited random carrier and filter materials.

[0081] At least one of the shafts can have a connection for a washing liquid, in order to supply washing liquid through the shaft stack to the non-filtrate. In addition, the washing liquid can be supplied in other ways than through a shaft and/or the stack. 

1. Device for filtering liquids; 1.1 with at least two shafts (1) which are parallel to each other or at an acute angle to each other arranged; 1.2 each shaft (1) carries a stack of filtering disks (2), which extend perpendicular to the shaft axis and which are connected to the shaft (1) in a rotationally fixed manner; 1.3 disks (2) of one disk stack are engaged in the spaces between the disks (2′) of an adjacent disk stack; 1.4 at least one of the shafts (1) is drivable; 1.5 at least one of the shafts (1) is hollow and is provided with bores (1.2); 1.6 at least some of the disks (2), which sit on one of the hollow shafts (1), have channels (2.4) inside them, with are conductively connected to the inside of their hollow shaft (1); 1.7 between each pair of adjacent disks (2) of a shaft is a ring-shaped distancing element (3); 1.8 the distancing element (3) is sealed in relation to the adjacent disks (2); 1.9 the distancing element (3) is connected to the shaft (1) in a rotationally fixed manner; 1.10 the distancing element (3) is oversized in relation to the shaft (1), so that a channel (4) is formed between the inner surface of the distancing element (3) and the outer surface of the shaft (1), this channel extending at least over part of the length of the shaft (1); 1.11 the distancing element (3) contains a support ring (3.1) as well as two sealing rings (3.2) allocated to each support ring (3.1).
 2. Device according to claim 1, characterized by the following features: 2.1 the support ring (3.1) consists of a relative hard, inflexible material; 2.2 shaft (1) and/or support (3.1) exhibit projecting parts (3.1.1, 3.1.2, 3.1.3), which cause a centering of the support ring (3.1) relative to the shaft (1); 2.3 each sealing ring (3.2) is arranged between the support ring (3.1) and the two disks (2) adjacent to the distancing element (3).
 3. Device according to claim 2, characterized by the fact that those sealing rings (3.2) are made from ductile and/or elastic ductile materials such as elastomers, easily ductile metals or their alloys, or graphite.
 4. Device according to claim 3, characterized by the fact that the sealing rings (3.2) are fastened to the support ring (3.1) by vulcanizing.
 5. Device according to claim 3 or 4, characterized by the fact that the sealing rings (3.2) exhibit a seat for the mounting of the adjacent disk (2).
 6. Device according to one of the claims 2 to 5, characterized by the following features: 6.1 the two sealing rings (3.2) of a support ring (3.1) are in each case located on a front surface of the support ring (3.1); 6.2 the two sealing rings (3.2) are connected by a bar (3.3), one-piece with them; 6.3 sealing rings (3.2) and bar (3.3) of a distancing element (3) form together a double-tee-section or a U-beam.
 7. Device according to one of the claims 2 to 6, characterized by the fact that shaft (1) and/or support rings (3.1) exhibit grooves (1.1), which serve the purpose to create a rotationally fixed connection between shaft (1) and support rings (3.1).
 8. Device according to one of the claims 2 to 7, characterized by such a material choice for the shaft (1), the disks (2), the support ring (3.1) and the sealing rings (3.2) that the shaft (1) on the one hand exhibits during heat exposure the same length growth, like the disks (2), the support rings (3.1) and the sealing rings (3.2) in their whole on the other hand.
 9. Device according to one of the claims 1 to 8, characterized by the following features: 9.1 the structural components comprising the shafts (1, 1′) and disks (2, 2′) are located in a liquid-tight reservoir (10, 10′); 9.2 the reservoir (10, 10′) exhibits a casing (10.3, 10.3′) enclosing the structural components as well as a lid (10.5, 10.5′); 9.3 the shafts (1, 1′) are over-mounted in each case at an end in the reservoir (10, 10′) and sealed against this reservoir (10, 10′).
 10. Device according to claim 9, characterized by the following features: 10.1 two single reservoirs are intended, which in each case contain one structural component and which are assembled to a complete reservoir; 10.2 the casings (10.3, 10.3′) of the two single reservoirs are assembled aligned to each other, in such a manner that the lids (10.5, 10.5′) of the two single reservoirs (10, 10′) are turned away from each other. 10.3 the free ends of the shafts (1, 1′) are facing each other.
 11. Device according to claim 9, characterized by the following features: 11.1 two single reservoirs are intended, which in each case contain one structural component and which are assembled to a complete reservoir; 11.2 the casings of the two single devices are assembled aligned to each other and exhibit in the assembly point a partition wall; 11.3 the shafts (1, 1′) of the two single reservoirs are mounted only in a medium area of the partition wall, and the seal-free ends of the shafts 1, 1′ are turned away from each other.
 12. Device according to claim 11, characterized by the fact that the two single reservoirs (10, 10′) enclose a single, undivided area.
 13. Device according to claims 11 or 12, characterized by the fact that the partition wall (10.8) exhibits passages to create a conducting connection between the two areas enclosed by the single reservoirs (10, 10′).
 14. Device according to one of the claims 9 to 13, characterized by the fact that a swiveling device is allocated to the reservoir (10) and/or the single reservoirs (10, 10′) in order to swivel them from the vertical position into the horizontal position.
 15. Device according to one of the claims 10 to 14, characterized by the fact that the single reservoirs (10, 10′) exhibit only one, joint casing.
 16. Device according to one of the claims 9 to 15, characterized by the fact that the casings of the reservoirs are cylindrical.
 17. Device according to one of the claims 9 to 15, characterized by the fact that the casings of the reservoirs deviate from the cylindrical shape.
 18. Device according to claim 17, characterized by the fact that the casings of the reservoirs are in the shape of a truncated cone.
 19. Device according to claim 17, characterized by the fact that the casings of the reservoirs are in the shape of a three-center curve when viewed in a cross-section perpendicular to the axis.
 20. Device according to one of the claims 9 to 19, characterized by the fact that the outline of the casings matches the outline of the disk stacks.
 21. Device according to one of the claims 9 to 20, characterized by the fact that the diameter of the disks of a stack is dimensioned in such a manner that the enveloping line of the stack has a shape that deviates from the regular cylinder shape.
 22. Device according to claim 21 characterized by the fact that the enveloping line of a disk stack is shaped like a cone.
 23. Device according to one of the claims 9 to 22, characterized by the fact that the shafts of the stacks are inclined towards each other.
 24. Device according to claim 23, characterized by the fact that the disks deviate from a flat shape and are for example spherical or plate-like.
 25. Device according to one of the claims 1 to 24, characterized by the following features: 25.1 the reservoir (10, 10′) has the shape of a regular cylinder; 25.2 the area, which is between the inner surface of the casing (10.3, 10.3′) of the reservoir (10, 10′) and the outer circumferences of the disk stacks adjacent to each other, contains applications e.g. a heat exchanger, e.g. for keeping the product to be treated at a moderate temperature.
 26. Method for operating a device for filtering liquid with at least two parallel or at an acute angle to each other arranged shafts, whose each carries a stack of disks, which extend perpendicular to the shaft axis and which are connected to the shaft in a rotationally fixed manner, in such a manner that the disks of one disk stack engage in the spaces between the disks of an adjacent disk stack, preferably according to one of the claims 1 to 24, characterized by the following features: 26.1 the shafts (1) are driven in the same direction of rotation; 26.2 the shafts (1) are driven intermittently, so that after a time interval of actuation a time interval of standstill follows.
 27. Method according to claim 26, characterized by the fact that the time intervals of the standstill are a multiple of the time interval of the actuation.
 28. Method according to claim 26 or 27, characterized by the fact that the relative velocities of plane elements opposite each other of two adjacent disks are constant in radial direction.
 29. Device according to one of the claims 26 to 28, characterized by the following features: 29.1 the pressure on the side of the non-filtrate is in the range between 0.2 and 50 bar, preferably between 0.5 and 10 bar; 29.2 the outfall of treated medium from the individual hollow shafts can be adjusted separately; 29.3 the pressure on the outlet side of the hollow shaft is controlled to values within the range of −0.999 (vacuum) up to 49.99 bar.
 17. Device according to one of the claims 9 to 15, characterized by the fact that the casings of the reservoirs deviate from the cylindrical shape.
 18. Device according to claim 17, characterized by the fact that the casings of the reservoirs are in the shape of a truncated cone.
 19. Device according to claim 17, characterized by the fact that the casings of the reservoirs are in the shape of a three-center curve when viewed in a cross-section perpendicular to the axis.
 20. Device according to one of the claims 9 to 19, characterized by the fact that the outline of the casings matches the outline of the disk stacks.
 21. Device according to one of the claims 9 to 20, characterized by the fact that the diameter of the disks of a stack is dimensioned in such a manner that the enveloping line of the stack has a shape that deviates from the regular cylinder shape.
 22. Device according to claim 21, characterized by the fact that the enveloping line of a disk stack is shaped like a cone.
 23. Device according to one of the claims 9 to 22, characterized by the fact that the shafts of the stacks are inclined towards each other.
 24. Device according to claim 23, characterized by the fact that the disks deviate from a flat shape and are for example spherical or plate-like.
 25. Device according to one of the claims 1 to 24, characterized by the following features: 25.1 the reservoir (10, 10′) has the shape of a regular cylinder; 25.2 the area, which is between the inner surface of the casing (10.3, 10.3′) of the reservoir (10, 10′) and the outer circumferences of the disk stacks adjacent to each other, contains applications e.g. a heat exchanger, e.g. for keeping the product to be treated at a moderate temperature.
 26. Method for operating a device according to one of the claims 1 to 25, characterized by the following features: 26.1 the pressure on the side of the non-filtrate is in the range between 0.2 and 50 bar, preferably between 0.5 and 10 bar; 26.2 the outfall of treated medium from the individual hollow shafts can be adjusted separately; 26.3 the pressure on the outlet side of the hollow shaft is controlled to values within the range of −0.999 (vacuum) up to 49.99 bar.
 27. Method for operating a device for filtering liquid with at least two parallel or at an acute angle to each other arranged shafts, whose each carries a stack of disks, which extend perpendicular to the shaft axis and which are connected to the shaft in a rotationally fixed manner, in such a manner that the disks of one disk stack engage in the spaces between the disks of an adjacent disk stack, preferably according to one of the claims 1 to 25, characterized by the following features: 27.1 the shafts (1) are driven in the same direction of rotation; 27.2 the shafts (1) are driven intermittently, so that after a time interval of actuation a time interval of standstill follows.
 28. Method according to claim 27, characterized by the fact that the time intervals of the standstill are a multiple of the time interval of the actuation.
 29. Method according to claim 27 or 28, characterized by the fact that the relative velocities of plane elements opposite each other of two adjacent disks are constant in radial direction. 